Here’s one of the Oxford English Dictionary’s definitions of accept:
To endure (an event, situation, or person) with patience or resignation; to tolerate, submit to; to come to terms with.
And here’s one of their definitions of respect:
transitive. In favourable sense: to treat or regard with deference, esteem, or honour; to feel or show respect for.
To accept someone’s decision means I respect their right to make that decision, not that I respect that decision.
(For me to respect a decision my necessary and sufficient condition is that it is based on critical thinking.)