Which speaks to much more dire organizational issues - that nobody can throw up a red flag and say "hold the eff up, we've reached a scale where this is broken and we need to address it."
I would say this is actually the norm... In most orgs the leadership is not highly technical and this is always a hard sell.
The best you can hope for after a "hold the eff up" rewrite is for everything to keep working the same "but it's more hardened/scalable/modular/blah blah", and the worst you can hope for is to screw up some critical business process while the kinks are worked out.
Also, there is rarely any incentive for anyone from Joe Developer all the way up to C level to even call for this in the first place.
Unless the developers are HAProxy itself and made a module for HAProxy to log in to SQL databases (which it doesn't do by default) this is not even remotely related to the developers.
HAProxy logs syslog messages, in a configurable format and to a destination of your choosing. All you have to do is to setup your favorite logging agent between fluentd/logstash/syslog-ng to listen on syslog and forward messages to a SQL database.
I know ;-) Hence my lawyer-ish choice of wording (default, module). HAProxy has some real nice features, especially the 1.8+ versions. We used to have configuration management tooling reconfigure and reload it, later on it get hot-reloads which was nice and then it got consul support so we could just feed consul and it all would work like magic. Love it.
My point was more about logging something straight in to a RDBMS wasn't much of a default at any point in time. Earlier on it was too expensive, and later on better systems came along. Some systems have built in text analysis and time series data specifics, but why would you worry about those when you have ElasticSearch and Kibana for most generic setups. Even before that you have syslog and a lot of log parsing libraries that worked great (well, unless you used windows event logs which has pros and a lot of cons).
Because as a database administrator, you often have to solve hosting problems without telling your developers to rewrite all their code.