They’re two sides of the same coin.
UKIP are their closest political match.
I think you are mistaken.
I have no problem, i really don't, with your views on Scotland however extreme they might come off, intentionally or not. Or in particular the SNP, heck i have plenty critical to say often. But i think you are making a very surface level link (to UKIP), and it is incorrect. I have no intention of 'defending' the snp, i certainly am no fan of nationalism myself, i condemn the type you describe. But you do seem genuine and intelligent enough for discussion, so i'll offer more/other perspective, take what you want from it, in relation to your UKiP comparison specifically.
I've read both manifestos. Over a number of elections. The parties are nothing alike. As i pointed out elsewhere, SNP have been governing Scotland for the best part of two dacades, and have a range of inclusive progressive policies, that are difficult to disagree with. They are (the policies rather than the party) imho more realistic versions of the Scottish Greens' ones. The party is the closest to what labour represented back when it used to be a credible party for the people. Which is why they have hoovered up almost all their voters. Yes their core thing is Independence. That will never change. But they portray that as their believed method by which to deliver their promises, rather than their end goal. I'm not saying i believe that, but that is what they clain to stand for. Just fyi, the greens also advocate independence, they do have a handful of seats in SP, nobody gives them a hard time for being nationalist cunts.
I'm not going to bother with UKiP, their manifesto is shorter than this post, and i think we all know what it is. Which is why they disappeared ovenight post brexit. the SNP have been about long before indyref, and grew much stronger after it. Partly, because the independence movement has grown, yes, but actually largely, because after indyref, those that would have voted for them as a party, but didnt because they disagreed with independence, started voting for them thinking that issue was dealt with. Till brexit came and the SNP weaponised it, and again lost some of those votes. Either way, they'l be about for a while.
I think Rascal has nailed it above. I'll add to that that people often mistakenly refer to them as the Scottish Nationalist Party. it is not. it is National. Now in no way am i claiming they arent in fact nationalists as such. but there is a nuance, to what comes first. And it isnt anti-english btw. It takes a nationalist that considers Westminster English rather than of the UK to think that. Although i'l admit, the SNP MPs do often get on my tits. But then i find the whole westminster model chauvinistic and lame at times.