To be sure, I’m a big fan of Ancestry.com in general. It’s unequalled... That said, not so regarding their handling of DNA test results from other suppliers, or more precisely their absolute lack thereof. Luckily, if you tested with one of the other providers (because there arevadvantages to that), having your results uploaded to all the others (except Ancestry) leaves your resulting absence from Ancestry... Insignificant.
Especially, because I suspect it's fair to say that most serious family researchers who were tested via Ancestry (you know which ones I mean, the ones who’ll actually respond when you contact them about a match 😀) also uploaded their results to all the other databases as well. So you’ll find them anyway... and they you.
From my perspective, Ancestry not taking your test results into their database when these came from another provider much more is a ’Bug’... than a ’Feature’