I've occasionally noticed, and commented on and downvoted lower quality, link-only answers, and you've definitely got a lot of rep - and well, if I thought one of your answers wasn't good, I'd consider downvoting and commenting. Not everyone might do the latter. In your case these would be link-only answers, with some older, bountied questions if I recall ...
If you want to retain the reputation previously earned and, after all, you did earn it, then making the answer Community Wiki would protect it and the answer would remain for posterity.
Wouldn't that be the simplest way? Especially if a caveat were added to the answer stating that it may no longer be applicable to new systems.
Making any change without knowing the intention of the downvoter seems pointless. Maybe they just downvoted you because they don't like you simply for being the user with the most reputation on the site.
I also get downvotes all the time on different sites, it doesn't bother me at all and I never even had the thought that this needs to be prevented.
Consider it done.
The ideal approach would have been to flag the non-answers. Once the third answer by a new user is deleted, a question is automatically protected by the system.
If a question doesn't have more than three deleted answers, it generally shouldn't be protected. We don't want to artificially block users from posting valid solutions.
This behaviour is by design. The idea is that a user is not considered to have enough experience with the topic of the site, so only rep earned on the site is counted: Why is the Association Bonus ignored when trying to answer a protected question?
Part of the boilerplate includes:
To answer it, you must have earned at least 10 reputation on this site.
This is because the question was protected. Protected questions bar anyone under 10 rep (earned from posts on the site) from being able to post answers.
Questions often get protected because they usually net "me too!" and "damn I had the same problem, can anyone light a bulb up in here?" answers which aren't.
Protection has been removed from this question.
From the FAQ:
Who can answer a protected question?
Users with 10 or more reputation can answer a protected question. However, the +100 account association bonus is ignored for this check2, so users with the association bonus require 110 reputation to answer protected questions. In other words, all users must have earned 10 or more reputation on that ...
As @Nifle said, you could protect a question so it won't attract spam (or otherwise bad answers) when it's reopened.
Since the question about the best IRC client for Windows … cough doesn't seem to be around anymore, and there never was a good chance of it being reopened anyway, I don't think it would have been necessary to protect it in the first place.
I agree that old technology should not be a basis for downvoting. The Meta discussions you linked to focus on obsolete information, and that is one source of the problem. But I have a different take on a more prevalent cause of the phenomenon.
You mention one downvote leading to more. Voting doesn't affect movement to the active questions list, so ...
Surely some sort of optional label like "obsolete" would be applicable to show that the answer was good and relevant at the time of posting but may not be now. Down-voting makes no sense as
the answer is still likely to have high(ish) marks and may be accepted
the answer may be the most correct answer to a question which may itself be out-of-date (in this ...
It has 2 deleted answers, most of which were terrible. Some people just ruin it for the rest of us.
I'll unlock it - if you can write a good meta post, I can expect you to write a good, as self contained as possible answer with necessary information on how to use it.
It is an unusual way to answer, so I suggest treating it like a software ...
Would considering a system which required a commented reason 'why' (even if limited in visibility) on downvotes to answers over whatever age (3 years, 5 years, etc) be a potential fix? Or maybe only the 'first' downvote after that time?