Yes, it is considered objectionable. If you wish to promote your site,
the only acceptable thing is to put the URL in your sig, and make
significant (meaningful) posts (IOW, participate and be helpful).

Otherwise, it is SPAM and you will loose far more than you gain.

There likely will be objections. It's called "spamming" and is much
frowned upon in a help group like this one.
That being said, no one will complain too vociferously if you just
post the URL once or twice.  Don't over do it! Regular readers will
likely visit it once  and bookmark the site for future reference if it
offers value. If it doesn't, count on getting savaged in any follow-up
posts.
These are just my opinions and I speak only for myself.
FWIW
YMMV
DFB

I won't buy from spammers.  I will pointedly go out of my way to avoid
them or their shops too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's