Agreed, too many people loosely use betting to mean either casino gambling or sports betting and people that know this can sometimes find this to be a pain and people need to make an effort to distinguish the two by saying so explicitly.
Not everyone is able to distinguish between the two different types of gambling and often do not make an effort to show the differences between them. The irony is that all those who do not distinguish between them will be those who prefer slot games only because they can achieve a quick win and do not need to wait until the end of the matches in sports betting. Also, online games are diverse, and available at any time, unlike sports betting, which is determined by the dates of the tournaments.
Slot games, for example, are the most popular, although they may be the least profitable. The point is that users are ignorant of the basics of the game algorithms and always expect that the game providers are reliable, and this is enough for them to prefer them over sports betting or other online games such as roulette or dice.
There is a clear difference between casino games and sport games, though most sport games have the casino versions and I believe that is one of the reasons some persons confuse the both to be Thesame. Those who don't have the knowledge of what gambling is or how gamble is played are the ones with this confusion because its obvious, and just as you have highlighted, sport games do have times and seasons meanwhile casino is continuous without breaks. Though the both are gamble but casino easily leads one to addiction because of how fast the results are determined, and trust me majority like it quick and easy.