I'm not a Republican, but the whole "stolen seat" thing is kind of overstating it because it implies that Garland would have become a justice for the SCOTUS, which is unlikely. It was stupid for the GOP to refuse a vote for Garland (stupid on multiple levels but even just strategically - they could have blocked Garland just via voting, there was no need to take it a step further and refuse a vote altogether and cause so much rancor), but regardless Garland was most likely not going to be on the SC, so the seat was not stolen. Legally it doesn't appear that they did anything technically wrong, but I think it's fair to say that having a vote would have been the right thing to do (notwithstanding some cases in the past where people such as Biden suggested a different course of action).
But let's be clear: both sides have, are, and continue to behave like children. Is what the GOP did stupid? You bet! Is the Dem handling of Gorsuch stupid? Most definitely. It's worth noting that the GOP senators in the past voted to seat justices that were quite liberal, but in the end relented because the candidate was qualified and there was not a good reason not to. With Gorsuch there's no real debate that he is very qualified, and yet few Dems voted for him - they voted against purely as retaliation.
And so the Dems did something stupid in retaliation for something stupid the Reps did. And the Reps did that stupid thing because of what Dems did to them before that. And the Dems did that thing because of what the Reps did even earlier. It's been going on for so long that we're at the point where neither side can claim any sort of moral high ground - it's pure, deep-rooted, partisan politics, and anyone who tries to argue that one of those two sides is better-behaving than the other is turning a blind eye to past events.
To everyone who is frustrated by this, you have to realize that Dem and Rep are two sides of the same coin. Both are almost comically hypocritical and neither consistently acts in the best interest of the USA. They have reached the point where so much of their identity is defined by not being the other side that I don't think there is any way for either party to fix themselves.
I watched a lot of the Gorsuch hearings and I came away with two main conclusions: (1) Gorsuch would make a great justice - I don't agree with him on various points, but he's sane and sincere and intelligent and it's not hard to imagine him being a fair judge. (2) The senators from both major parties are complete morons. So much pettiness and shallow posturing. So much snide smirking and pretentiousness. It was embarrassing for both parties.
It's time we moved the conversation away from "Reps are bad" vs "Dems are bad" because that will get us nowhere. Both are terrible and possibly beyond repair. But as long as we allow ourselves to believe that one side is acting in good faith while the other side is not, we will make zero progress. Both are incredibly corrupt. Both major parties have a list of "sins" so long that neither should be allowed in power.