Dear google,
About half a decade ago, I created a gmail account (maybe longer—not so sure anymore). After testing it out for a while, I decided that it wasn't for me; but as a gmail account comes with a google account for free, I didn't throw it out.
As time went on, I added a few other things to that account. I try to limit its use a bit, but I do own a few android devices (for lack of a better alternative), and I do use adsense on my website, and all of these are linked to my existing google account; so I don't want to throw it away.
I don't ever read mail sent to my gmail account, though; I prefer to read my mail in a local mail client (I used mutt for about a decade, having switched to thunderbird recently). Since it kept happening that people thought I would read my gmail account (which I do still use for XMPP, in spite of your recent crippling of that service), I configured an autoresponder on gmail to warn people off, and told them to use my main mail address instead of the gmail one. Additionally, I configured my main mail addresses (plural; they're really aliases) as "secondary" addresses on my gmail account, so that people who try to send mail to me could figure out where to actually send it before seeing the autoreply.
Unfortunately, for some reason you seem to have interpreted that as "screw his MX records and DNSSEC, we'll just intercept anything coming from our servers and going to Wouter Verhelst as going to his gmail account".
There's a word for that. I'm not going to use it.
You could just autoforward mail sent to gmail as explained here: https://support.google.com/mail/answer/10957?hl=en.
Alternatively you could check your gmail inbox with a local client using POP or IMAP.
Yes, there are shitloads of workarounds which I could implement. That's besides the point.
The fact of the matter is, I have an MX in my DNS, and this MX is verified by DNSSEC. That, and only that, should define where mail to my mail address needs to be routed.
Anything else is completely and utterly wrong.
I don't know about what "should" be the case. I do know that there have been several cases of people sending me email through google servers where the mail was redirected to my gmail address, and I did not see the mail until I logged in to gmail.
Apparently there are cases where the mail will still arrive correctly, as you've shown by sending me a mail from gmail. Still, that doesn't mean there's no problem.